/Engine/Plugins/Experimental/PCG/Source/PCG/Public/PCGSubgraph.h
Can be overridden to add more custom params (like in BP).
virtual [TArray](API\Runtime\Core\Containers\TArray)< [FPCGSettingsOverridableParam](API\Plugins\PCG\FPCGSettingsOverridableParam) > GatherOverridableParams() const